Certain 2-substituted-4,6-diamino-5-pyrimidinecarboxaldehydes

ABSTRACT

NOVEL 2,4,7 - TRISUBSTITUTED-PYRIDO(2,3-D)PYRIMIDINE-6CARBOXAMIDES HAVE BEEN PRODUCED WHICH HAVE CENTRAL NERVOUS SYSTEM DEPRESSANT ACTIVITY AND ARE USEFUL PHARMACOLOGICAL AGENTS IN THE CALMING OF ANIMALS.

United States Patent 3,795,674 CERTAIN 2-SUBSTlTUTED-4,6-DIAMINO-5- PYRIMIDINECARBOXALDEHYDES Arthur A. Sanfilli, Havel-town, and Doug H. Kim, Wayne,

Pa., assignors to American Home Products Corporation, New York, N.Y.

No Drawing. Original application June 18, 1970, Ser. No. 47,571, now Patent No. 3,725,405. Divided and this application Aug. 7, 1972, Ser. No. 278,316

Int. Cl. C07d 51/42 US. Cl. 260256.4 N 3 Claims ABSTRACT OF THE DISCLOSURE Novel 2,4,7 trisubstituted-pyrido[2,3-d]pyrimidine-6- carboxamides have been produced which have central nervous system depressant activity and are useful pharmacological agents in the calming of animals.

This is a division of Ser. No. 47,571, which was filed on June 18, 1970, and is now U.S. Pat. No. 3,725,405.

DESCRIPTION OF THE INVENTION The invention is concerned with compounds of Formula I wherein R is selected from the group consisting of phenyl,

halophenyl, (lower)alkoxyphenyl, (lower)alkylphenyl and (lower)alkyl thio; R is selected from the group consisting of (lower)alkoxyethyl, hydroxy(lower)alkyl,

(lower)alkoxycarbonylmethyl, phenethyl, halophenethyl, (lower) alkoxyphenethyl, (lower)alkylphenethyl, and

wherein R and R when not concatenated are independently selected from the group consisting of hydrogen, (lower)alkyl and (lower)alkoxy; when R, and R are concatenated they form a radical selected from the group consisting of morpholino, piperazinyl, imidazolinyl and pyrrolidinyl; n is an integer of from 1 to about 4; R is selected from the group consisting of hydroxy and amino.

Also within the scope of the invention are the novel compounds of Formula H which are intermediates in the synthesis of the valuable pharmacological agents of Formula I.

NHa

N CHO wherein R is the same as hereinabove described.

When used herein and in the, appended claims, the

term (lower)alkyl contemplates [hydrocarbon radicals, straight and branched, of from about 1 to about 6 carbon 3 ,795,674 Patented Mar. 5,1974

"Ice

bis(substituted)malonamide is added and the reaction mixture is refluxed and the 2,4,7-trisubstituted-pyrido-' [2,3-d]pyrimidine-6-carboxamides are then recovered from the reaction mixture.

Two methods are useful for the isolation of the products from the reaction mixture. It may be possible to separate the product by filtering the precipitate that readily forms in the heated reaction mixture. As an alternative method it may be necessary to cool the reaction mixture in ice to separate the product as a crystalline precipitate. The product may then be purified by recrystallization from ethanol, aqueous dimethylformamide etc.

The starting materials for the preparation of Formula II are commercially available or may be prepared by techniques well known to those skilled, in the art.

In the pharmacological evaluation of the biological activity of the compounds of this invention, the in vivo effects were tested as follows.

The compound was administered orally or intraperitoneally to three mice (14 to 24 grams) at each of the following doses: 400, 127, 40 and 12.7 milligrams per kilogram of host body weight (MPK). The animals were watched for a minimum of two hours during which time signs of general stimulation (i.e., increased spontaneous motor activity, hyperactivity on tactile stimulation, twitching), general depression (i.e., decreased spontaneous motor activity, decreased respiration), autonomic activity (i.e., miosis, mydriasis, diarrhea) were noted.

The compounds of this invention induce central nervous system depressant elfects at a dose of 127 to 400 MPK. Thus, the compounds of the invention have demonstrated utility as pharmacologically active compounds in experimental and comparative pharmacology and are of value in the treatment of mammals, e.g. mice, rats, etc., who are responsive to treatment with central nervous depressant agents. Specifically the compounds may be administered for the purpose of inducing a calming elfect in mammals.

When the compounds of this invention are employed as described above, they may be administered alone or in combination with pharmacologically acceptable carriers, the proportion of which is determined by the solubility and chemical nature of the compound, chosen route of administration and standard pharmacological practice. For example, they may be administered orally in the form of tablets or capsules containing such excipients as starch, milk, sugar, calcium carbonate and the like. They may be administered orally in the form of solutions which may contain coloring and flavoring agents or they may be administered by parenteral injection, e.g., intramuscular injection. The injectionable solution may contain other 1 solutes such as sodium chloride or glucose in a suflicient atoms; illustrative members of the group being methyl,

ethyl, n-propyl, i-propyl, n-butyl; t-butyl, n-pentyl,

n-hexyl arid the like. The term (lower)alkoxy contem quantity to render the solution isotonic.

The dosage of the pharmacological therapeutic agents of the invention will vary with the route of administration and the particular compound chosen. Furthermore, it will vary with the particular subject under treatment.

" Generally, treatment is initiated with small dosages substantially less than the optimum dose of the compound. Thereafter, the dosage may be increased by small increments until the optimum eflect under the circumstances is l I. .W V J EXAMPLE I 4,6-diamino-2-phenyl-S-pyrimidenecarboxaldehyde To 50 ml. of concentrated ammonium hydroxide solutionin a pressure flask is added 15 g. of 4,6-dichloro-2- phenyl 5 pyrimidinecarboxaldehyde. The mixture is heated on a steam bath for one hour and a sufiicient quantity of ethanol is added to solubilize the mixture. Heating is continued for an additional hour. The reaction is cooled in ice and the crystalline product that is deposited (9.5 g.) is recrystallized from ethanol. The product has a M.P. of 217-218" C.

. Analysis.Calcd. for C H N O (percent): C, 61.67; H, 4.71; N, 26.16. Found (percent): C, 61.50; H, 4.40; N, 26.13.

EXAMPLE II 4,6-diamino 2 methylthio-S-pyrimidinecarboxaldehyde is prepared as in Example I from g. of 4,6-dichloro-Z-methylthio-S- yrimidinecarboxaldehyde in 80 ml. of concentrated ammonium hydroxide. The product amounts to 10 g. Recrystallization from ethanol yields an analytical sample, M.P. 228230 C.

-Amzlysis. Calcd. for C H N OS (percent): C, 39.12; H, 4.37; N,'30.41; S, 17.40. Found (percent): C, 39.08; H, 4.38; N, 30.06; S, 17.15.

EXAMPLE III 4,7-diamino-N-cyclohexyl-2- methylthio pyrido [2,3-d] pyridine-G-carboxamide EXAMPLE IV 4,7-diamino-N-(2-dimethylaminoethyl)-2-(methylthio) pyrido [2,3-d] pyrimidine-6-carboxamide To a solution of 0.23 g. of sodium in absolute ethanol is added 1.2 g. of 4,6-diamino-2-methylthio-5-pyrimidinecarboxaldehyde and 1.1 g. of 2 cyano-N-(Z-dimethyh aminoethyl)acetamide. The reaction mixture is heated under reflux for 2 hours and allowed to stand overnight in the refrigerator. A yellow crystalline product is depos- 4 ited. Recrystallization from ethanol yields 0.3 g. of product, M.P. 297300 C., V

Analysis.-Calcd. for C13H19NqOS (percent): C, 48.58; H, 5.96; N, 30.51; S, 9.97. Found (percent): C, 48.52; H, 5.85; N, 30.45; S, 9.99.

, EXAMPLE v 4,7-diamino-N-(Z-methoxyethyl)-2-phenylpyrido[2,3-d] pyrimidine-6-carboxamide To 0.69 g. of sodium in 100 ml. of ethanol is added 6.12 g. of 4,6-diamino-2-phenyl-5-pyrimidinecarboxaldehyde and 4.26 gof 2-cyano-N-(Z-methoxyethyl)acetamide. The reaction mixture is heated under reflux with stirring for one hour. After cooling in ice a precipitate is deposited. Recrystallization from ethanol yields 1.0 g. of product, M.P. 258261 C.

Analysis.-Calcd. for C H N O (percent): C, 60.34; H, 5.36; N, 24.84. Found (percent): C, 60.08; H, 5.26; N, 24.90.

EXAMPLE VI 4,7-diamino-N- (2-morpholinoethyl) -2-phenylpyrido [2,3-d] pyrimidine-G-carboxamide To 0.69 g. of sodium in 100 ml. of ethanol is added 6.12 g. of 4,6-diamino-Z-phenyl-S-pyrimidinecarboxaldehyde and 5.92 g. of 2-cyano-N-(2-morpholinoethyl)acetamide. The reaction mixture is heated under reflux for 20 minutes during which time a yellow precipitate is deposited. The reaction mixture is cooled in ice and filtered. The filter cake amounts to 5.9 g. Recrystallization from aqueous dimethylformamide yields 5 g. of product, M.P. 299-300 C.

Analysis.-Calcd. for C20H23N702 (percent): C, 61.05; H, 5.89; N, 24.92. Found (percent): C, 61.17; H, 5.95; N, 24.87.

EXAMPLE VII 4-a'mino-7-hydroxy-N- (Z-methoxyethyl)-2-phenylpyrido [2,3-d] pyrimidine-6-carboxamide To a solution containing 0.69 g. of sodium in ml. of absolute ethanol is added 6.1 g. of 4,6-diamino-2- phenyl-S-pyrimidinecarboxaldehyde and 5.9 g. of N,N- bis(2 methoxyethyl)malonamide. The reaction mixture is heated under reflux with stirring for 3 hours and then cooled in ice. The yellow precipitate which is deposited is collected on a filter and recrystallized from aqueous dimethylformamide. The product amounts to 2 g., M.P. 360".

Analysis.-Calcd. for C17H17N506 (percent): C, 60.17; H, 5.05; N, 20.64. Found (percent): C, 59.60; H, 4.94; N, 20.79.

EXAMPLE VIII By methods analagous to those employed above, the following compounds are prepared:

NHz

BIQ

1. A compound selected from the group consisting of:

CHO Ii -LN NH! wherein R is selected from the group consisting of phenyl, halophenyl, (lower)alkoxyphenyl, (lower)alkylpheny1 and (lower)alkylthio.

2. A compound as described in claim 1 which is: 4,6- diamino-2-phenyl-5-pyrimidinecarboxaidehyde.

amino-Z-methylthio-S-pyrimidinecarboxaldehyde.

OBrien et al.: Chem. Abstracts, 69:27369 (1968).

RICHARD J. GALLAGHER, Primary Examiner U.S. C1. X.R. 

